The world No.1 never goes away. Over five sets there is nothing he likes more than grinding an opponent into the concrete. If he can get into a bit of Serbian shirt-ripping and a couple of roars down the barrel of the TV lens, then so much the better.

Despite being a foreigner, the New York crowd love him because he bares his soul on court and he has made the final four years in a row. This is his eighth straight quarter-final at the US Open and his 22nd straight quarter-final at grand-slam level. So he is one of the greats, and the man to beat.

Djokovic will hope he is at his shirt-ripping best (Picture: Darron Cummings/AP Photo)

But it is precisely because of all these achievements that Murray will relish the challenge. Can you imagine how much fun Murray is going to have trying to take him down? He is going to love it. He has beaten his old rival in the finals of the US Open and Wimbledon.

He might be the underdog but he could do it again.

This is Murray’s chance to make a statement in 2014. He was gutted by his dismissal at the hands of Grigor Dimitrov at Wimbledon and will want to put that right.

Murray on his way to victory over Tsonga (Picture: Timothy A Clary/Getty Images)

He is one of the few players who can get under the Serbian’s skin. That back surgery Andy had last year took the wind out of his sails. This is a chance to rejoin the elite.

Every match they play is intriguing because they have so clearly paid the price in learning their craft. This could be the match of the tournament if Andy is at his best.